Here is the site: http://www.rawvision.com
Site recently migrated from multisite to single-site install (but I'vb done this 30+ times without incident, so rather confused)
New images upload properly to sites/rawvision.com/files/
Presets generate and show up in directory at sites/rawvision.com/files/imagecache/[PRESETNAME]/filename.

Everything shows up properly when viewing any given page.

HOWEVER - images are being RE-generated on every page call. Obviously this is a ridiculous performance drag on this image-heavy site!
I look at Firebug and I see that the path for the image is incorrect - (for example)